A certain reaction has a delta H= -75 kJ and an activation energy of 40 kJ. A catalyst is found that lowers the Activation energy of the forward reaction by 15 kJ. What is the activation energy of the reverse reaction in the presence of this same catalyst?
Ea forward - Eareverse = delta H
25 - Er = -75
solve for Er.
e
Well, if we want to find the activation energy of the reverse reaction, we can use a little chemical humor.
Imagine the forward reaction as a person hiking up a mountain. The activation energy is like the energy needed to climb up to the top. Now, imagine the catalyst as a helpful friend coming along and giving the hiker a boost, so they don't have to work as hard to reach the summit.
So, if the activation energy of the forward reaction was originally 40 kJ, and the catalyst lowers it by 15 kJ, it means the hiker only has to make an effort of 25 kJ to climb up.
Now, when we talk about the reverse reaction, it's like going down the mountain. The catalyst is still there, being the helpful friend. So, if the forward reaction only needs 25 kJ of effort, it means the reverse reaction also needs 25 kJ of effort, because the catalyst is still lending a hand.
Therefore, the activation energy of the reverse reaction in the presence of the same catalyst would be 25 kJ.
Hope that brings a smile to your face, even if it's an uphill battle!
To find the activation energy of the reverse reaction in the presence of the same catalyst, we need to use the concept of the Arrhenius equation, which relates the rate constant (k) of a reaction to the activation energy (Ea) and the temperature (T).
The Arrhenius equation is given by: k = A * e^(-Ea/RT), where k is the rate constant, A is the pre-exponential factor, Ea is the activation energy, R is the gas constant (8.314 J/(mol·K)), and T is the temperature in Kelvin.
Since the activation energy of the forward reaction is 40 kJ and the catalyst lowers it by 15 kJ, the new activation energy of the forward reaction in the presence of the catalyst is: Ea_forward = 40 kJ - 15 kJ = 25 kJ.
Now, we need to find the activation energy of the reverse reaction with the same catalyst. The reverse reaction is the opposite of the forward reaction, so the activation energy of the reverse reaction would be the opposite of the activation energy of the forward reaction.
Thus, the activation energy of the reverse reaction in the presence of the same catalyst would be: Ea_reverse = -25 kJ.
Therefore, the activation energy of the reverse reaction in the presence of this same catalyst is -25 kJ.
To find the activation energy of the reverse reaction in the presence of the catalyst, we can use the fact that the activation energy difference between the forward and reverse reactions remains the same.
Given:
Forward reaction activation energy (without catalyst): Ea1 = 40 kJ
Forward reaction activation energy (with catalyst): Ea2 = Ea1 - 15 kJ = 40 kJ - 15 kJ = 25 kJ
Since the activation energy difference is the same for both the forward and reverse reactions, we can calculate the activation energy of the reverse reaction by subtracting the decreased activation energy of the forward reaction by the catalyst from the original activation energy of the reverse reaction.
Activation energy of the reverse reaction = Activation energy of the forward reaction (without catalyst) - Activation energy difference
= 40 kJ - 15 kJ
= 25 kJ
Therefore, the activation energy of the reverse reaction in the presence of the same catalyst is 25 kJ.